I found these on Ebay. Are they very well made?
https://www.ebay.com/itm/6ea-NEW-PHILIPS-146910-LIGHT-BULB-SLS-14W-TRIPLE-TUBE-SCREW-BASE-CFL-Soft-White/303279521303?epid=3012086656&hash=item469cde3e17:g:xvwAAOSw6eRddqBJ

Yes, these were some of the best CFLs Philips made.

Yes, these were some of the best CFLs Philips made.

OK, I`ll probably get some.

Yes these are good quality

But the question is, whether mainly the electrolytic capacitor survive the power up after all those years of sitting (it may need reforming but that is impossible without disassembling the thing first)...

From my experience, the electrolytic capacitors in older CFLs are a lot more robust than they're given credit for, as i've never had one suddenly fail in a NOS lamp.

What if not using a resistor as the current limit, but only ramp up DC voltage slowly with a low impedance DC source ? The lamp starting won't affect the capacitor voltage in this case, so it won't start flashing with the capacitor voltage oscillating. Could powering it with DC undervoltage damage the rest of the ballast ?

What if not using a resistor as the current limit, but only ramp up DC voltage slowly with a low impedance DC source ? The lamp starting won't affect the capacitor voltage in this case, so it won't start flashing with the capacitor voltage oscillating. Could powering it with DC undervoltage damage the rest of the ballast ?

Undervoltage may damage the lamp - operating it for quite some time with cold cathodes will sputter them quickly.

I lit up an NOS Norelco SL*18 lamp made in 1983. Lit with no problems whatsover.

I lit up an NOS Norelco SL*18 lamp made in 1983. Lit with no problems whatsover.

But isn't that using series reactor ballast and a preheat circuit? Then there is no component to degrade by storage...

I got some and they work fine.

Undervoltage may damage the lamp - operating it for quite some time with cold cathodes will sputter them quickly.

Would it even strike at voltages low enough to be a problem ? (when ramping up, not letting it start at higher voltage and going down)

Would it even strike at voltages low enough to be a problem ? (when ramping up, not letting it start at higher voltage and going down)

The resonance boost up the voltage. It clearly ignites the discharge when the voltage just reaches the diac breakover (see the ghost flashing common with the 2way switch arrangements) - so about 40V is enough to ignite it even with cold electrodes.

But is the applied votlage sufficeint to strike the discharge ? For all i know it might just be running at above resonance, heating the cathodes continuously, but unable to do anything else...

And what if the capacitor forming is "skipped" from below lamp striking voltage to voltage at which the cathodes are just about warm enough to not sputter - Assuming it is still far from full rectified line voltage, would it still be acceptable for forming the capacitor ?

The flashing CFLs on many two way ciruits is a good proof, I think, the 40V is enough to ignite the discharge. Just the capacitor charge purged into the inverter once per minute is in no way capable to heat up the electrodes, yet CFLs are flashing there.
Of course it depends on the exact design, but mainly the first electronic models had nothing to prevent the cold ignition.